[Reeve of shinra]

Deffinitely go with the owned liscence over the leased, it will save you money in the long run and the $30 renewal fee almost feels like a steal considering how satisfied i've been with the product (going on 4 years now).

As Colin F said, installing mods are rather simple as the instructions are usually well documented. Only tip here is to note your edits for easier upgrading. Something like: "//Begin this hack here" can be sufficient.